The applicants proposed a technique for continuing development of a real-time, three dimensional (3-D) ultrasound based visualization system for in-OR dose planning, real-time guidance of radioactive implants or in-OR post-implant assessment for treating prostate cancer. The system would include a real-time 3-D endorectal imaging probe and supporting 2-D, 3-D and virtual reality visualization interfaces. Present techniques using transrectal ultrasound guidance for brachytherapy are difficult to implement and often result in unacceptable rates of complications. The aim of the proposed technique is to consolidate the total implant procedure, reduce complication rates and improve local control by optimization of seed implantation during ultrasound-guided brachytherapy. PROPOSED COMMERCIAL APPLICATION: NOT AVAILABLE